It replace your reality with virtual computer generated environment.
Virtual Reality (VR) also known as Computer Simulated Reality. It is a computer technology that replicates an environment, real or imagined and simulates a user’s physical presence and environment to allow for user interaction. Virtual realities artificially create sensory experience which can include sight, touch, hearing, and smell. Virtual Realities are displayed either on a computer screen or with a special virtual reality headset (head-mounted display).